You need to get your G on the dyno to find out IF or how much of a problem you might have. Post the results here and we can give you an analysis.

 

Johnboy, How many miles do you have on your G now? A dyno will definitely help especially if you can get mixture readings too; you'll be able to see any flatspots or troughs in the power curve as well as a good idea of how well your ECU is providing fuel. It does sound like you have some issues but most of the things I can think of that might make your car perform in the way you describe would also be likely to throw a CEL. (too lean, too rich, o2 sensor bad, misfires etc etc)

...I know this sounds retarded but have you jacked up the car to make sure that the wheels are moving unhindered... rear brakes aren't binding or something crazy like that? How does the car sound when you get on it etc etc? Are you noticing anything else other than poor performance? (I'm trying to think of non-ECU controlled / diagnosed issues)

 

I have had no problems at all with mine after almost 60K miles. Believe it or not, its faster and runs better the more I drive it. Best car I have ever owned. I do hear of more problems with the newer G's though. I think the whole "dont buy a first year car" advice has now inverted. A car company will put its brightest and best on the line for a new strategic release and the quality is first rate. After a few years, they put the second string in and pull the best onto the new hot model like the M. I wouldnt buy an 05 or 06 G because of this. The new G's are definitely not better than what I have. I know, I've driven the loaners.

 

Sorry but I owned a 04 G35 and now a 05, and you are completely wrong. The 05 G's are much better and they have much fewer problems at this moment of time. 1st year car only is the 2003 G35 not the 05.

 

Update:

I found that my right-rear quarter panel had been repainted by the dealer, and after polite complaining about that, and the engine, and the sticking radio button, and the tweeter rattle, I managed to get them to take the black G as a purchase price trade-in on another one. Now I have a Diamond Graphite/Stone sedan with perfect paint and an engine that seems more linear in its power delivery, but I won't do any timed 0-60 and 0-100 runs just yet (100 miles on the clock).

 

Nice, sounds like they took care of you. Enjoy your new baby

 

i have an 05AT DG/Stone with sport package and about 7200mi's on it now. I agree about the throttle calibration. 1/2 throttle is strong and almost feels like a turbo without the whine after it passes 3500rpm. Similar to a 280zx turbo i had in high school. There's definitly some kind of swith-over at 3500 WOT doesn't feel like it's pulling much harder - just winds out a little farther.

BTW, finally put the K&N on last night (i did the ztube a few months ago). I've noticed a slight difference...the moan from the ztube is more prominent now. That ztube really brings the AT engine sounds to life - it's a complete nbo-brainer. If you have an AT then get the ztube. I like the sound as it's changing to the next higher gear and the throttle rolls down and then engages. Also fun is the the kickdown from 2nd back into 1st - it will break the tires loose on old asphalt. I know - "big deal" or "grow up". But getting that in a reasonably priced rwd 4dr V6 family sedan is such a plus.

The tire spinning from a standing start really is variable. Last winter I could spin almost entirely thru 1st gear - no brake torques or any other tricks. But later found my tires were around 45 psi and obviously the roads/tires were cold. NOw with 32 psi and hot roads, maybe a little chirp here and there from a stop. But nothing like before. Even though I'd argue the car is making slightly more power now. Regardless it really is a fantastic "all-in-one" ride for the money.

 

Good job. I'm glad they were able to work with you. Sounds like this was headed for a horror story but not anymore.